fix: SASS deprecated lighten, darken and color methods

[ghiscoding]

Description

fixes issue #40849

• another deprecation from SASS which is again displaying a load of console warnings
• more info on SASS website: https://sass-lang.com/documentation/breaking-changes/color-functions/

Motivation & Context

latest SASS version v1.79.x and higher are now showing a bunch of deprecation warnings as shown below.

Type of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring (non-breaking change)
• Breaking change (fix or feature that would change existing functionality)

Checklist

• I have read the contributing guidelines
• My code follows the code style of the project (using npm run lint)
• My change introduces changes to the documentation
• I have updated the documentation accordingly
• I have added tests to cover my changes
• All new and existing tests passed

Live previews

• https://deploy-preview-{your_pr_number}--twbs-bootstrap.netlify.app/

Related issues

[julien-deramond]

Thanks for your work here @ghiscoding
However, Bootstrap 5 still needs to support node-sass, so we can't use sass:color as done in this PR (see #40864 (comment)).
Thanks for your work on this! I'm going to close it for now to help keep our backlog manageable. Feel free to reopen it if you come up with a different or new solution :)